X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=scheme.4th;h=c4a08cfa4a61d7a8625e78d5eccdd035cf14248b;hb=d2dc6c641693e0db30a8e11d7cb404148ba95838;hp=7ac6355287f14b249c1a201d0de7d517756fc81d;hpb=a966a509dd23259423e21c55d973403b88b86ea4;p=scheme.forth.jl.git

diff --git a/scheme.4th b/scheme.4th
index 7ac6355..c4a08cf 100644
--- a/scheme.4th
+++ b/scheme.4th
@@ -180,7 +180,7 @@ console-i/o-port obj@ current-input-port obj!
 objvar symbol-table
 
 : duplicate-charlist ( charlist -- copy )
-    2dup nil objeq? false = if
+    nil? false = if
         2dup car 2swap cdr recurse cons
     then ;
 
@@ -239,7 +239,7 @@ objvar symbol-table
 ;
 
 
-: cstr>charlist ( addr n -- symbol-obj )
+: cstr>charlist ( addr n -- charlist )
     dup 0= if
         2drop nil
     else
@@ -256,13 +256,7 @@ objvar symbol-table
     count
 
     cstr>charlist
-    drop symbol-type
-
-    2dup
-
-    symbol-table obj@
-    cons
-    symbol-table obj!
+    charlist>symbol
 
     create swap , ,
     does> dup @ swap 1+ @
@@ -277,6 +271,7 @@ create-symbol if            if-symbol
 create-symbol lambda        lambda-symbol
 create-symbol λ             λ-symbol
 create-symbol begin         begin-symbol
+create-symbol apply         apply-symbol
 
 \ }}}
 
@@ -336,7 +331,7 @@ objvar vals
 : get-vars-vals ( var env -- vars? vals? bool )
 
     begin
-        2dup nil objeq? false =
+        nil? false =
     while
         2over 2over first-frame
         get-vars-vals-frame if
@@ -408,7 +403,9 @@ global-env obj!
 
 objvar macro-table
 
-: lookup-macro ( name_symbol -- proc? bool )
+( Look up macro in macro table. Returns nil if
+  no macro is found. )
+: lookup-macro ( name_symbol -- proc )
     macro-table obj@
 
     begin
@@ -418,11 +415,13 @@ objvar macro-table
         car car objeq? if
             2swap 2drop
             car cdr
-            true exit
+            exit
         then
+
+        cdr
     repeat
 
-    2drop false
+    2swap 2drop
 ;
 
 : make-macro ( name_symbol params body env -- )
@@ -442,6 +441,8 @@ objvar macro-table
             set-cdr!
             exit
         then
+
+        cdr
     repeat
 
     2drop
@@ -1029,6 +1030,31 @@ parse-idx-stack parse-idx-sp !
 : macro-definition? ( obj -- obj bool )
     define-macro-symbol tagged-list? ;
 
+: macro-definition-name ( exp -- mname )
+    cdr car car ;
+
+: macro-definition-params ( exp -- params )
+    cdr car cdr ;
+
+: macro-definition-body ( exp -- body )
+    cdr cdr ;
+
+objvar env
+: eval-define-macro ( obj env -- res )
+    env obj!
+
+    2dup macro-definition-name 2swap ( name obj )
+    2dup macro-definition-params 2swap ( name params obj )
+    macro-definition-body ( name params body )
+
+    env obj@ ( name params body env )
+
+    make-macro
+
+    ok-symbol
+;
+hide env
+
 : if? ( obj -- obj bool )
     if-symbol tagged-list? ;
 
@@ -1040,7 +1066,7 @@ parse-idx-stack parse-idx-sp !
 
 : if-alternative ( ifobj -- alt|false )
     cdr cdr cdr
-    2dup nil objeq? if
+    nil? if
         2drop false
     else
         car
@@ -1080,14 +1106,14 @@ parse-idx-stack parse-idx-sp !
     2swap ( env explist )
 
     \ Abort on empty list
-    2dup nil objeq? if
+    nil? if
         2drop none
         2swap exit
     then
 
     begin
         2dup cdr ( env explist nextexplist )
-        2dup nil objeq? false =
+        nil? false =
     while
         -2rot car 2over ( nextexplist env exp env )
         eval
@@ -1157,10 +1183,10 @@ parse-idx-stack parse-idx-sp !
     2swap
 ;
 
-: apply ( proc argvals )
+: apply ( proc argvals -- result )
         2swap dup case
             primitive-proc-type of
-                drop execute
+                drop execute     
             endof
 
             compound-proc-type of
@@ -1179,11 +1205,24 @@ parse-idx-stack parse-idx-sp !
                 R> drop ['] eval goto-deferred  \ Tail call optimization
             endof
 
-            bold fg red ." Object not applicable. Aboring." reset-term cr
+            bold fg red ." Object not applicable. Aborting." reset-term cr
             abort
         endcase
 ;
 
+: macro-expand ( proc expbody -- result )
+    2swap
+    2dup procedure-body ( expbody proc procbody )
+    -2rot 2dup procedure-params ( procbody expbody proc argnames )
+    -2rot procedure-env ( procbody argnames expbody procenv )
+    
+    -2rot 2swap
+    flatten-proc-args
+    2swap 2rot
+
+    extend-env eval-sequence eval
+;
+
 :noname ( obj env -- result )
     2swap
 
@@ -1248,26 +1287,52 @@ parse-idx-stack parse-idx-sp !
 
     application? if
 
-        2over 2over
-        operator
+        2over 2over ( env exp env exp )
+        operator ( env exp env opname )
+
+        2dup apply-symbol objeq? if
 
-        find-macro-proc nil objeq? if
-            \ Regular function application
+            2drop 2swap ( env env exp )
+            cdr 2dup car 2rot ( env expbody real-opname env )
+            eval ( env expbody proc )
+            2swap cdr
+            nil? false = if car then ( env proc real-operand )
 
-            2swap eval
-            -2rot
-            operands 2swap list-of-vals
+            2rot eval ( proc argvals )
+
+            pair-type istype? false = if
+                bold fg red ." Error: apply requires a list of operand arguments." cr
+                reset-term abort
+            then
 
             apply
-        else
-            \ Macro function evaluation
+            exit
+        then
 
-            2swap 2drop 2swap ( env mproc exp )
+        2dup lookup-macro nil? false = if
+             \ Macro function evaluation
 
-            apply 2swap ( expanded-exp env )
+            ( env exp env opname mproc )
+            2swap 2drop -2rot 2drop cdr ( env mproc body )
 
+            2dup print cr
+            macro-expand
+            2dup print cr
+
+            2swap
             ['] eval goto-deferred
         then
+
+       \ Regular function application
+
+        2drop ( env exp env opname )
+
+        2swap eval ( env exp proc )
+        -2rot ( proc env exp )
+        operands 2swap ( proc operands env )
+        list-of-vals ( proc argvals )
+
+        apply
         exit
     then
 
@@ -1471,6 +1536,49 @@ variable gc-stack-depth
 
 \ }}}
 
+\ ---- Loading files ---- {{{
+
+: charlist>cstr ( charlist addr -- n )
+
+    dup 2swap ( origaddr addr charlist )
+
+    begin 
+        nil? false =
+    while
+        2dup cdr 2swap car 
+        drop ( origaddr addr charlist char )
+        -rot 2swap ( origaddr charlist addr char )
+        over !
+        1+ -rot ( origaddr nextaddr charlist )
+    repeat
+
+    2drop ( origaddr finaladdr ) 
+    swap -
+;
+
+: load ( addr n -- finalResult )
+    open-input-file
+
+    empty-parse-str
+
+    ok-symbol ( port res )
+
+    begin
+        2over read-port ( port res obj )
+
+        2dup EOF character-type objeq? if
+            2drop 2swap close-port
+            exit
+        then
+
+        2swap 2drop ( port obj )
+
+        global-env obj@ eval ( port res )
+    again
+;
+
+\ }}}
+
 \ ---- Primitives ---- {{{
 
 : make-primitive ( cfa -- )
@@ -1480,14 +1588,8 @@ variable gc-stack-depth
     \ 2dup ." Defining primitive " type ." ..." cr
 
     cstr>charlist
-    drop symbol-type
-    
-    2dup
-
-    symbol-table obj@
-    cons
-    symbol-table obj!
-
+    charlist>symbol
+  
     rot primitive-proc-type ( var prim )
     global-env obj@ define-var
 ;
@@ -1503,7 +1605,7 @@ variable gc-stack-depth
             arg-count-error
         then
     else
-        -rot 2dup nil objeq? if
+        -rot nil? if
             arg-count-error
         then
         
@@ -1526,56 +1628,10 @@ include scheme-primitives.4th
 
 \ }}}
 
-\ ---- Loading files ---- {{{
-
-: charlist>cstr ( charlist addr -- n )
-
-    dup 2swap ( origaddr addr charlist )
-
-    begin 
-        2dup nil objeq? false =
-    while
-        2dup cdr 2swap car 
-        drop ( origaddr addr charlist char )
-        -rot 2swap ( origaddr charlist addr char )
-        over !
-        1+ -rot ( origaddr nextaddr charlist )
-    repeat
-
-    2drop ( origaddr finaladdr ) 
-    swap -
-;
-
-: load ( addr n -- finalResult )
-    open-input-file
-
-    empty-parse-str
-
-    ok-symbol ( port res )
-
-    begin
-        2over read-port ( port res obj )
-
-        2dup EOF character-type objeq? if
-            2drop 2swap close-port
-            exit
-        then
-
-        2swap 2drop ( port obj )
-
-        global-env obj@ eval ( port res )
-    again
-;
-
-:noname ( args -- finalResult )
-    2dup 1 ensure-arg-count
-    car string-type ensure-arg-type
-
-    drop pair-type
-    pad charlist>cstr
-    pad swap load
-; make-primitive load
+\ ---- Standard Library ---- {{{
 
+    s" scheme-library.scm" load 2drop
+    
 \ }}}
 
 \ ---- REPL ----